Edwards, who built a lead of more than 800 points in the first half of the season, stumbled through the second half of the year before putting away the title with an 11th-place run in the O'Reilly Challenge. He leads runner-up David Reutimann by an insurmountable 552 points with two races to go.

"It's really amazing to be a Busch Series champion," said Edwards, who has won four times season. "I can't tell you how exciting that is and what it means to me."

Team owner Jack Roush was relieved that Edwards got it done Saturday.

"The rhythms in this business will just drive you crazy," Roush said. "We had an unbelievable start to the year and, of course, it was unbelievable and we had to give a lot of it back. It means a lot to me to see Carl win his first championship in NASCAR.

"We were a better race team than we looked like at the end with crashes and parts and things breaking. Those guys definitely deserve that championship and I'm happy for them.

Edwards, a Nextel Cup regular who has done double duty all season, finished third in the Busch Series as a rookie in 2005 and was runner-up to fellow Cup star Harvick last year.

For a while, it seemed as if he might blow the huge lead.

"We just had a lot of bad luck," Edwards said. "I just couldn't believe it. I'll never forget Kentucky (in June). We were dominant, a half-second faster than the field, and I had already picked who I was going to give the trophy to. We had it won and got wrecked there and it just seemed like it wouldn't stop after that.

"But I'm just glad we could overcome that and just go on and win this championship."

For Harvick, running a limited Busch schedule this season after his runaway title in 2006, it was business as usual as he won for a series-high sixth time in 24 starts in 2007. It was his 32nd career victory, moving past Jack Ingram into second place behind Mark Martin, who has 47 wins.

"Just to be up there with Jack Ingram and Mark Martin and all they guys who made this series, that's pretty special," said Harvick, who has won five of the last seven Busch races and also has won a record four times at Texas, breaking a tie with Martin.

"It's been a lot of fun to drive this Richard Childress Chevrolet over the last few years. And this place has been really good to us."

He beat Kyle Busch to the finish line by 3.486 seconds most of the front straightaway on the 1.5-mile oval. Denny Hamlin finished third, followed by Clint Bowyer and Matt Kenseth. Sixth-place Brad Keselowki was the highest finishing Busch Series regular.

Tony Stewart, who started alongside pole-winner Reutimann in the front row, had the dominant car most of the day, leading 114 of the first 129 laps. But a collision with the lapped car of Kyle Krisiloff put a hole in the right front of the two-time Cup champion's car and forced him to make a long pit stop for repairs. He finished seventh after pitting on lap 130 and falling to 16th, the last car on the lead lap.

Greg Biffle then passed Hamlin for the lead on lap 140 and appeared on the way to his first Busch victory of the season until he pitted with what he thought was a deflating front tire on lap 166. It turned out the tire was fine, but Biffle fell a lap off the pace and finished 16th.

That left Harvick in the lead, with Busch his closest pursuer. But Busch couldn't get close.

"He just got out into that clean air after the last restart and that was it, he was gone," the disappointed Busch said.

Harvick said his team made the right adjustments later in the race.

"We were able to race hard on the restarts and get by a couple of guys," he said. "We were running down Biffle when it looked like he had some kind of tire problem. After that, we were in good shape."